NailedBy: AI Nail Art Try-On

NailedBy lets you preview nail designs on your own hand before the salon—so you skip regrets and enjoy nail art with confidence.

Inspiration

The idea for NailedBy was inspired by the way nail artists share their work on social media using tags like “nailed by 〇〇.” This habit reflects a strong culture of visual storytelling and personalization in the nail community.

Today’s beauty enthusiasts are constantly seeking inspiration on platforms like TikTok, Instagram and Pinterest. They frequently visit salons or do DIY nail care at home and want a more personalized, convenient way to explore, plan, and track their nail styles. Existing solutions offer nail art simulation but lack a truly personal and continuous experience. NailedBy aims to bridge that gap by offering an end-to-end nail journey: diagnosis, design recommendation, simulation, and record-keeping—all in one app, utilizing state-of-the-art AI models.

What It Does

NailedBy is an app designed to make nail care and style planning effortless, personalized, and shareable.

Key Features

1) AI-Powered Nail Diagnosis

Users simply take a photo of their hand. The app analyzes nail shape (square, oval, round, etc.), nail condition (dryness, cracks, discoloration—purely from a beauty perspective), and skin tone around the nails to recommend colors that best complement the user’s natural undertone.

2) AI-Powered Nail Art Try-on

Users can preview suggested designs directly on their own nails through AI-based image synthesis. In the MVP, this will be a lightweight photo overlay, with AR functionality as a future upgrade. Users can also upload their own inspirations, tweak colors/shapes, and preview them—making salon visits easier with a clear visual reference.

3) Personalized Care Suggestions

Based on the diagnosis, users receive tailored care tips (e.g., hydration, cuticle oil, nutrition hints).

4) Nail History & Sharing

Every design, diagnosis, and simulation can be saved as a record. Users can look back at their “nail journey” and share styles on social media seamlessly.

How we built it

We built and launched NailedBy in just two weeks by harnessing AI-powered coding tools. Our lean, agile team of four—designers and engineers working side by side—collaborated seamlessly to turn the idea into reality at speed, without sacrificing quality. This accelerated development cycle enabled rapid iteration and allowed us to deliver a refined user experience from day one.

Challenges we ran into

Designing a product aligned with real user insights was more difficult than expected. Our team of four men in their 20s and 30s had no direct experience with nail care or nail art. While we identified potential demand through TikTok posts—such as nail condition diagnosis and recreating nail art—we struggled to define features that would truly resonate with users. Luckily, several interns who matched our target demographic were available. By having them test the app, collecting real-time feedback, and iterating on design and development, we refined the product direction.

We also faced technical hurdles in optimizing prompt engineering for Gemini, which we used to generate nail designs. Since outputs varied depending on the source images, we had to repeatedly adjust, test, and refine prompts across numerous use cases. Although this was a painstaking process, it enabled us to significantly improve the accuracy and reliability of the generated results within a short timeframe.

Accomplishments that we’re proud of

We managed to take the product from idea generation to release in just about two weeks. By involving test users throughout the process and incorporating their feedback quickly, we created a product that already demonstrates strong user value despite its early stage. Achieving this speed of iteration and refinement was a major accomplishment for our team.

What we learned

We learned that even with an unpolished, hypothesis-driven product, it is far more effective to release quickly, gather feedback from real users, and refine continuously. This approach accelerates the path to building something truly useful.

We also realized the importance of choosing a theme with strong user passion. Because many potential users around us were genuinely interested in nail care, we were able to collect enthusiastic feedback that helped us pivot early—from focusing on AI-driven design suggestions to enabling users to apply their preferred designs directly to their hands.

Another key lesson was that deep domain expertise isn’t a prerequisite for product creation. With the right users to consult and collaborate with, even a team lacking direct knowledge can build a valuable product. Going forward, we recognize the need to continue improving pricing strategies, trial designs, feature expansion, and organic growth—but the experience reinforced the advantages of releasing fast and iterating with users at the center.

What’s next for NailedBy

1) Personalized Nail Art Suggestions

AI suggests matching nail art designs—colors and styles that suit their nail shape and aesthetic preferences. Recommendations are displayed in a card-style UI, allowing users to save or “like” their favorites.

2) Nail Art 'Discovery' Gallery We’re exploring a feature where, upon opening the app, users can browse a wide collection of nail art designs—personalized color matches for their hands, seasonal trends, and creations generated by other users. Our hypothesis is that enabling users to seamlessly visualize a chosen design directly on their own hands would deliver strong value, and we’re currently developing this capability.